Orbital angular momentum mode determination with partial receive circle

Abstract

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first wireless communication device may transmit, to a second wireless communication device, information indicating positions of orbital angular momentum (OAM) antennas of a partial receive circle of the first wireless communication device that are operational. The partial receive circle is part of a full receive circle that includes positions with the OAM antennas that are operational and one or more positions that do not have OAM antennas that are operational. The first wireless communication device may receive an OAM mode to use for reception of an OAM signal at the OAM antennas that are operational. The first wireless communication device may then receive the OAM signal according to the OAM mode. Numerous other aspects are described.

What is claimed is: 
     
         1 . A first wireless communication device for wireless communication, comprising:
 a memory; and   one or more processors, coupled to the memory, configured to:
 transmit, to a second wireless communication device, information indicating positions of orbital angular momentum (OAM) antennas of a partial receive circle of the first wireless communication device that are operational, wherein the partial receive circle is part of a full receive circle that includes the positions with the OAM antennas that are operational and one or more positions that do not have OAM antennas that are operational; 
 receive, from the second wireless communication device, an OAM mode to use for reception of an OAM signal at the OAM antennas that are operational; and 
 receive, from the second wireless communication device according to the OAM mode, the OAM signal at the OAM antennas that are operational. 
   
     
     
         2 . The first wireless communication device of  claim 1 , wherein the one or more processors are configured to derive the OAM signal for the positions that do not have OAM antennas that are operational based at least in part on virtual rotational OAM coefficients that are applied to the OAM signal received at the positions of the OAM antennas that are operational. 
     
     
         3 . The first wireless communication device of  claim 1 , wherein the one or more processors are configured to:
 receive, from the second wireless communication device, a plurality of OAM modes to use for reception of a plurality of OAM signals at the OAM antennas that are operational; and   receive, from the second wireless communication device according to the plurality of OAM modes, the plurality of OAM signals at the OAM antennas that are operational.   
     
     
         4 . The first wireless communication device of  claim 3 , wherein the one or more processors are configured to demultiplex the plurality of OAM signals at the OAM antennas that are operational based at least in part on virtual rotational OAM coefficients that are applied to the plurality of OAM signals received at the positions of the OAM antennas that are operational. 
     
     
         5 . The first wireless communication device of  claim 1 , wherein the information includes a radius of the full receive circle. 
     
     
         6 . The first wireless communication device of  claim 1 , wherein the one or more processors are configured to transmit, to the second wireless communication device, change information indicating a change of one or more OAM coefficients for one or more OAM antennas of the partial receive circle. 
     
     
         7 . The first wireless communication device of  claim 1 , wherein the one or more processors are configured to transmit an indication to use a virtual rotational OAM scheme. 
     
     
         8 . The first wireless communication device of  claim 1 , wherein the one or more processors are configured to transmit, to the second wireless communication device, a value of a partial circle coefficient that indicates a proportion of a channel gain or a signal-to-noise ratio (SNR) by the partial receive circle relative to a channel gain or an SNR by the full receive circle, or a value change of the partial circle coefficient. 
     
     
         9 . A first wireless communication device for wireless communication, comprising:
 a memory; and   one or more processors, coupled to the memory, configured to:
 receive, from a second wireless communication device, information indicating positions of orbital angular momentum (OAM) antennas of a partial receive circle of the second wireless communication device that are operational, wherein the partial receive circle is part of a full receive circle that includes the positions with the OAM antennas that are operational and one or more positions that do not have OAM antennas that are operational; 
 transmit, to the second wireless communication device, an OAM mode to use for reception of an OAM signal, based at least in part on the information; and 
 transmit, to the second wireless communication device, the OAM signal using the OAM mode. 
   
     
     
         10 . The first wireless communication device of  claim 9 , wherein the one or more processors are configured to:
 transmit, to the second wireless communication device, a plurality of OAM modes to use for reception of a plurality of OAM signals, based at least in part on the information; and   transmit, to the second wireless communication device, the plurality of OAM signals using the plurality of OAM modes.   
     
     
         11 . The first wireless communication device of  claim 9 , wherein the information includes a radius of the full receive circle. 
     
     
         12 . The first wireless communication device of  claim 9 , wherein the one or more processors are configured to receive change information indicating a value change of one or more OAM coefficients of one or more OAM antennas of the partial receive circle. 
     
     
         13 . The first wireless communication device of  claim 9 , wherein the one or more processors are configured to select the OAM mode from among multiple OAM modes based at least in part on a signal-to-noise ratio (SNR) that is calculated for each of the multiple OAM modes. 
     
     
         14 . The first wireless communication device of  claim 13 , wherein the SNR is calculated for each of the multiple OAM modes as a function of one or more of: a square of a channel gain for the full receive circle, an oversampling coefficient, a total quantity of OAM antennas in a full transmit circle of the first wireless communication device, a base SNR value between a transmitting OAM antenna and a receiving OAM antenna, and a noise coefficient that is calculated from weights that are each a function of an OAM mode and a position of an OAM antenna of the second wireless communication device that is operational. 
     
     
         15 . The first wireless communication device of  claim 14 , wherein the one or more processors are configured to calculate the channel gain of an OAM mode for the full receive circle based at least in part on a circle radius or aperture radius of the full receive circle. 
     
     
         16 . The first wireless communication device of  claim 15 , wherein the one or more processors are configured to calculate a channel gain or an SNR of an OAM mode based at least in part on a proportion of a channel gain or an SNR for the partial receive circle relative to the channel gain or an SNR for the full receive circle. 
     
     
         17 . The first wireless communication device of  claim 15 , wherein the one or more processors are configured to calculate a channel gain or an SNR of an OAM mode based at least in part on a value of a partial circle coefficient that indicates a proportion of a channel gain or an SNR for the partial receive circle relative to a channel gain or an SNR for the full receive circle, or that indicates a value change of the partial circle coefficient, wherein the value of the partial circle coefficient or the value change of the partial circle coefficient is received from the second wireless communication device. 
     
     
         18 . The first wireless communication device of  claim 17 , wherein the partial circle coefficient is channel-relevant to the multiple OAM modes. 
     
     
         19 . The first wireless communication device of  claim 17 , wherein the partial circle coefficient is channel-irrelevant to the multiple OAM modes. 
     
     
         20 . The first wireless communication device of  claim 17 , wherein the one or more processors are configured to update one or more of the channel gain of an OAM mode or the SNR of an OAM mode based at least in part on the value change of the partial circle coefficient. 
     
     
         21 . The first wireless communication device of  claim 9 , wherein the one or more processors are configured to select the OAM mode with a greatest SNR. 
     
     
         22 . A method of wireless communication performed by a first wireless communication device, comprising:
 transmitting, to a second wireless communication device, information indicating positions of orbital angular momentum (OAM) antennas of a partial receive circle of the first wireless communication device that are operational, wherein the partial receive circle is part of a full receive circle that includes the positions with the OAM antennas that are operational and one or more positions that do not have OAM antennas that are operational;   receiving, from the second wireless communication device, an OAM mode to use for reception of an OAM signal at the OAM antennas that are operational; and   receiving, from the second wireless communication device according to the OAM mode, the OAM signal at the OAM antennas that are operational.   
     
     
         23 . The method of  claim 22 , further comprising deriving the OAM signal for the positions that do not have OAM antennas that are operational based at least in part on virtual rotational OAM coefficients that are applied to the OAM signal received at the positions of the OAM antennas that are operational. 
     
     
         24 . The method of  claim 22 , further comprising transmitting, to the second wireless communication device, change information indicating a change of one or more OAM coefficients for one or more OAM antennas of the partial receive circle. 
     
     
         25 . The method of  claim 22 , further comprising transmitting, to the second wireless communication device, a value of a partial circle coefficient that indicates a proportion of a channel gain or a signal-to-noise ratio (SNR) for the partial receive circle relative to a channel gain or an SNR for the full receive circle, or a value change of the partial circle coefficient. 
     
     
         26 . A method of wireless communication performed by a first wireless communication device, comprising:
 receiving, from a second wireless communication device, information indicating positions of orbital angular momentum (OAM) antennas of a partial receive circle of the second wireless communication device that are operational, wherein the partial receive circle is part of a full receive circle that includes the positions with the OAM antennas that are operational and one or more positions that do not have OAM antennas that are operational;   transmitting, to the second wireless communication device, an OAM mode to use for reception of an OAM signal, based at least in part on the information; and   transmitting, to the second wireless communication device, the OAM signal using the OAM mode.   
     
     
         27 . The method of  claim 26 , further comprising selecting the OAM mode from among multiple OAM modes based at least in part on a signal-to-noise ratio (SNR) that is calculated for each of the multiple OAM modes. 
     
     
         28 . The method of  claim 27 , wherein the SNR is calculated for each of the multiple OAM modes as a function of one or more of: a square of a channel gain for the full receive circle, an oversampling coefficient, a total quantity of OAM antennas in a full transmit circle of the first wireless communication device, a base SNR value between a transmitting OAM antenna and a receiving OAM antenna, and a noise coefficient that is calculated from weights that are each a function of an OAM mode and a position of an OAM antenna of the second wireless communication device that is operational. 
     
     
         29 . The method of  claim 28 , further comprising calculating a channel gain or an SNR of an OAM mode based at least in part on a proportion of a channel gain or an SNR for the partial receive circle relative to the channel gain or an SNR for the full receive circle. 
     
     
         30 . The method of  claim 28 , further comprising calculating a channel gain or an SNR of an OAM mode based at least in part on a value of a partial circle coefficient that indicates a proportion of a channel gain or an SNR for the partial receive circle relative to the channel gain or an SNR for the full receive circle, or that indicates a value change of the partial circle coefficient, wherein the value of the partial circle coefficient or the value change of the partial circle coefficient is received from the second wireless communication device.